Lens.



H. W. HESS.

LENS. APPLICATIONFXLEDJUNE29,191F.

lutentvd Mar. .3, 1918) flfizveu for /ak 7 W 1/ a 7(7) JV. r/u 1/0 HARRYW. HESS, OF PROVIDENCE, RHODE ISLAND.

LENS.

Specification of Letters Patent.

Patented Mar. 5, 1918.

Application flled lux e 29, 1917. Serial No. 177,790.

To all wrwm it may comern:

Be it known that I, HARRY W. Hess, citizen of the United States, andresident of Providence, R. I., have invented certain new and usefulImprovements in Lenses, of which the following is a specification.

This invention relates to lenses for the transmission and refraction oflight rays and is intended to rovide'a lens for such purpose which shalreduce the most eflicient results by blen ing as uniformly as possiblethe transmitted light ra s over the area that is required to He iuminated. Such lenses may be effectively used for motor car head-lights,search 1i hts, and other purposes and serve to afl'o eflicientilluniination while intensity of the are. g The invention ementiallcomprises a main body or disk pro id with rows of convex bosses orprojections on one face in closely arranged series whose individualconvex elements progressiveli decrease in height and diameter from t eperipheral portion to the center of the disk as will be moreparticularly explained hereinafter.

" Referring to the drawings in which I have illustrated concreteapplications of the principles of this invention,

Fi re 1 is an elevation or front view of one' arm of the lens.

2 is a section thereof extending from the periphery to the center on theplane indicated by dotted line X.

Fig. 3 is an elevation or front view of a ortion of a lens having aslightly modiiied arrangement of the convex refracting elements, inWhich the radial series of elements are arranged on straight radiallines.

In the practice of this invention according to the form illustrated inFig. 1 the disk a of glass or other translucent material is formed withone plane surface as indicated at a while on the opposite side areformed a series of closely arranged convex elements which in this caseare arranged in series forming radial curves from the center to theperiphery as indicated by dotted line X in Fig. 1. It will also benoticed by reference to dotted line 3/ on Fig. 1 that the arrange mentof elements in this case is such that they form radiating curves inopposite directions the curves in one direction having a differentmodulus of curvature from those in the other direction. In this caseboth curves are in the form of logarithmic spirals which arran ementmakes possible'a greater." number of ifierent sizes of individual elesments, the sizes progressively doc i 1*". from the periphery to thecenter by' a. determined ratio and givin a amount of refraction to thelight rays ing through the entire lens. z

The convex elements 6 are preferably cit-f1". cular in cross-sectionalplanes intersecting 35 their individual axes at n t angles or per; alleltothe rear face a o the Jens.

3, The profile curvature of each individual element may be variedaccordinfg to the particular requirements of service r which the 7 lensis intended. If the curvature or contour of each element in a planeintersecting its central axis or, in other words, at right an Eles tothe rear face of the lens be of paraolic form there will be a greaterconcentration of the light rays passing through the central or apexportion of each convex element than if the elements be given a curvatureor contour of more nearly circular form.

While I prefer, generally speaking, to use an arrangement of the lightrefracting' bosses similar to that shown in Fig. 1,,in which they formoppositely curved series radiating from the center, nevertheless these86 elements may be arranged as shown in Fi 3 with each radiating seriesextending 1n straight lines from center to circumference. Thisarrangement. however, involves a greater ratio of reduction in size foreach 90 successive element in the series extending from thecircumference to the center while the :u'rnngemrnt of radiating curvesmakes Q possible to progressively reduce the size .f each successiveelement in the series by smaller ratio of difference- The resultanteffect particularly where elements of the parabolic contour or convexcurvature are employed is a diffusion of a portion of the rays with aforward projection of the strongest rays passing through the apex orcentral portions of the refractr ing elements, thereby greatly reducingthe dazzling or glare efl'ect of the transmitted lights while afl'ordimrabundant and strong illumination. The c ose order or arran es ment ofthe refracting elements enab es them to act with maximum obtainableeflZect on the entire body of light rays passing through the lens. 1

What I claim is:

1. A light transmitting lens embracing in its construction a disk oftranslucent material provide on one face with closely arranged series ofconvex bosses of circular contour, the individual bosses graduallyincreasing in size from center to circumference and being arranged inoppositely curved radiating spirals, substantially as described,

2. A light transmitting lens embracing in its construction a disk oftranslucent material provided on one face with closely arranged bossesgradually increasing in size 15 from center to circumference andarranged in oppositely curved radiating spiral rows terial one side ofwhich is a plane surface,

the op osite side being formed with closely arran ed series of convexbosses of circular form and having a parabolic cross sectional contour,said bosses gradually increasing in size from center to circumferenceand arranged in oppositely curved radiating spiral rows, substantiallyas described:

In witness whereof, I have subscribed the above specification.

HARRY W. HESS.

